Method and apparatus for regulating and terminating fluid flow

Abstract

A fluid valve for controlling flow of a fluid from an upstream region to a downstream region includes a housing having a fluid exit, a fluid entry member having a sidewall, and a shut-off member associated with the housing. The sidewall and the fluid entry member is formed with at least one regulating aperture for receiving fluid from the upstream region and a second aperture for receiving fluid from the upstream region. The fluid entry member is movably disposed within the housing such that the at least one regulating aperture has an effective area exposed to the upstream region that decreases as a pressure differential between the upstream region and the downstream region increases. The shut-off member is associated with the housing and the fluid entry member such that fluid flow through the second aperture is prevented when the difference in fluid pressure between the upstream region and the downstream region exceeds a desired value.

What is claimed is:  
     
       1. A fluid valve for controlling flow of a fluid from an upstream region to a downstream region, the fluid valve comprising: 
       a generally cylindrical housing having a fluid entrance and a fluid exit;  
       a fluid entry member having a generally cylindrical sidewall formed with at least one regulating aperture for receiving fluid from the upstream region, the side wall further formed with a second aperture for receiving fluid from the upstream region, the fluid entry member movably disposed within the housing such that the at least one regulating aperture has a total area exposed to the upstream region sufficient to allow a substantially constant rate of fluid flow through the fluid valve over a range of pressure differentials between the upstream region and the downstream region; and  
       a cap having a first end and a peripheral sidewall, the first end coupled to an end of the fluid entry member opposite the housing, the peripheral sidewall engaging the housing and preventing fluid flow through the valve when the difference in fluid pressure between the upstream region and the downstream region exceeds a desired value, and  
       wherein the second aperture is positioned closer to the cap than the at least one regulating aperture.  
     
     
       2. The valve of claim  1 , and further comprising an elastic member opposing, in at least one direction, motion between the housing and the cap. 
     
     
       3. The valve of claim  1 , wherein the fluid entry member and the cap define a clearance region. 
     
     
       4. The valve of claim  1 , wherein the cap is formed integral with the fluid entry member. 
     
     
       5. The valve of claim  1 , and further comprising a screw coupling the cap to the fluid entry member. 
     
     
       6. A fluid valve for controlling flow of a fluid from an upstream region to a downstream region, the fluid valve comprising: 
       a generally cylindrical housing having a fluid entrance and a fluid exit;  
       a fluid entry member having a generally cylindrical sidewall formed with at least one regulating aperture for receiving fluid from the upstream region, the side wall further formed with a non-regulating orifice positioned further upstream than the at least one regulating aperture for receiving fluid from the upstream region, the fluid entry member movably disposed within the housing such that the at least one regulating aperture has a total area exposed to the upstream region sufficient to allow a substantially constant rate of fluid flow through the fluid valve over a range of pressure differentials between the upstream region and the downstream region; and  
       a cap having a first end and a peripheral sidewall, the first end coupled to an end of the fluid entry member opposite the housing, the peripheral sidewall engaging the housing and preventing fluid flow through the valve, including the non-regulating orifice, when the difference in fluid pressure between the upstream region and the downstream region exceeds a desired value.  
     
     
       7. The fluid valve of claim  6 , wherein the peripheral sidewall of the cap and the sidewall of the fluid entry member define a clearance region. 
     
     
       8. The fluid valve of claim  6 , wherein the non-regulating orifice is generally circular.